Hydrocarbon extraction

ABSTRACT

CONTINUOUS EXTRACTION OF HYDROCARBONS FROM ASPHALTIC OR BITUMINOUS MATERIALS, SUCH AS &#34;TAAR SANDS,&#34; WITHIN A PRESSURISED VESSEL AT ELEVATED TEMPERATURES.

Filed March 26, 1971 WATER INVENTORS RUEL C.TERRY ROBERT E. LANE BYATTORNEY 3,738,929 Ice Patented June 12, 1973 Filed Mar. 26, 1971, Ser.No. 128,421

Int. Cl. Cg N04 US. Cl. 208--11 6 Claims ABSTRACT OF THE DISCLOSUREContinuous extraction of hydrocarbons from asphaltic or bituminousmaterials, such as tar sands, within a pressurised vessel at elevatedtemperatures.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to unique apparatus and method for recovering hydrocarbons fromnaturally occurring oil bearingmaterials; tar sands, for example. Moreparticularly this invention relates to an inexpensive method, utilizinga simple and compact equipment, for preferably continuously recoveringhydrocarbon from tar sands, for example, which may be mined in aconventional manner and introduced into the process in slurry form.

In the prior art, for example, pulverized tar sands are mixed with hotwater in a rotating conditioning drum which discharges on screensflooded with more hot water. Because this operation is carried out atatmospheric conditions maximum temperatures of only about 185 F. can bereached. The screen undersize, a mix of oil, sand and hot water, entersflotation cells where the mix is agitated and where air is added to forman oily froth which can be skimmed off the top. This material is dilutedwith naphtha and centrifuged prior to entering final clarification andstorage tanks.

This invention as described hereinbelow eliminates some of the steps ofthe prior art effecting savings in both equipment and simplicity ofmethod.

SUMMARY OF INVENTION In accordance with the invention, hydrocarbonbearing materials are introduced as a slurry into a centrifugalseparator where the material is substantially concentrated.

The concentrated material (separator underflow) discharges into a vesselcontaining hot water at a temperature in a controllable range of about200 F. to about 300 F. The difliculty of obtaining the 200 F.temperature at atmospheric conditions, because of the blending with coldmaterials, results in the temperature range of above 212 F. to about 300F. under pressure conditions for the hot water being preferable. Thistemperature is controlled by direct steam injection into the vessel insuch a fashion that it also aid-s in agitating the infiuent materials.As the material passes through the hot water zone the hydrocarbons arefreed from the gangue material and float to the surface of the water.Brine may be used in the slurry to aid in floating the hydrocarbons. Thehydrocarbons are removed in one embodiment through a float controlledautomatic valve at some upper level.

The application of heat reduces viscosity of the hydrocarbons and theirspecific gravities. Because the water preferentially wets the sandparticles and excludes oil particles, the oil particles are, therefore,freed from the sand. The lowered viscosity and hence lower surfacetension allows for the action of the water as described. Because the oilis lighter than the water a gravity separation takes place.

The cleansed material settles to the bottom of the vessel where it isautomatically flushed as tailings.

DETAILED DESCRIPTION OF THE EXTRACTION UNIT The drawing shows anelevational sectional view of one embodiment of an extraction unit.

In the embodiment shown in drawing, hydrocarbon bearing material such astar sands are introduced as a water-tar sand slurry into centrifugalseparator 1. The slurry is concentrated from approximately 30% tar sandsto approximately tar sands. This concentration is necessary in order tominimize heat requirements. The underflow or concentrated slurrydischarges into the extraction unit, as at 1A. A fluid level ismaintained in the extraction unit as indicated in section A by floodingsection D with cold water, the volume of which is regulated by controlvalve 3 which is actuated by level control mechanism 2.

As the bituminous materials move downward by gravity through section Athey must pass through steam sparge ring 5 as a result of direction bycone 14. Steam entering at this point provides heat to section A andalso provides positive agitation of the materials, a necessaryfunctionin cleansing the sand particles. The amount of steam isregulated by control valve 7 which is actuated by the temperaturesensing-transmitter device 6. Section A, as shown in the drawing, isdefined in this embodiment by (l) the upper level L of the fluidsurface, (2) the cone 14 and (3) the sides of the unit.

As the material moves from section A to section B through opening 8 inthe cone 14 the cleansed sands will continue their downward path whilethe lighter oils will tend to float into zone C. The hydrocarbon-waterinterface between zones B and C is controlled by removing hydrocarbonsthrough valve 13 which is actuated by level indicator-transmitter 12. Asshown in the embodiment described, zone B lies below the cone 14 andzone C is on top of zone B but also limited in its upward extent by thecone 14.

Heat is applied to section B by the introduction of steam through spargering 11, the volume of which is regulated by valve 10 which in turn isactuated by temperature sensing-transmitting device 9. The introductionof steam at this point further aids in cleansing the material andmaintains temperatures at described levels.

After passing through sparge ring 11 the cleansed sand enters section DWhere it is preferably continuously flushed out fixed exit orifice 4,although a valving arrangement could be provided.

The fixed orifice is sized such to provide enough restriction to allowmaintenance of pressures above the orifice at desired levels by theaddition, for example, of cold water into section D through for examplevalve 3.

Preferably the pressure drop through the orifice remains substantiallyconstant no matter what the varying characteristics of the slurry: forexample, fluctuation in the viscosity of the material going through theorifice. This is accomplished as stated by introducing water into theslurry at a point before it goes through the orifice and maintaining theflow of the liquid introduced such that the conditions set forth aboveoccur.

In one specific example of the embodiment described above, slurry madeup of tar sands and water is introduced into the separator to obtain arate of about 40 tons per hour of tar sand, with a resultanthydrocarbons output exiting from valve 13 at a rate of 5 to 15 bbls. perhour, depending upon the hydrocarbon content in the ore. In the range ofabout to 300 gallons per minute, for example, of cold water isintroduced into the cold water section in this specific example. Steamis introduced at a rate to maintain temperatures within the unit in arange from about 212 F. to 300 F.

Although the invention has been described with relation to water and tarsands in the slurry and in the unit, it is recognized that other fluids,such as oil, and other hydrocarbon bearing materials could be utilized.Having now illustrated the invention with relation to one illustrativeembodiment thereof.

I claim:

1. A method of removing asphaltic or bituminous liquids from hydrocarbonbearing materials by Washing said materials with a fluid comprisingsubstantially Water at temperatures above about 200 F.

2. A continuous method for extracting hydrocarbons from ore using acolumn of water comprising the steps of:

(a) providing a first upper zone wherein heated water is maintainedabove about 200 F. to about 300 F.;

(b) introducing said ore into the top of said first upper zone to freethe hydrocarbon from said ore,

(c) introducing steam into said first zone to provide heat thereto andagitate said water;

(d) moving said ore under the action of gravity alone through said firstzone and from said first zone through an exit opening and into a secondlower zone of relatively cold water;

(e) introducing cold water into the second zone;

(f) maintaining the level of said first zone of water as a result ofintroducing water into said second zone;

(g) moving said ore under the influence of gravity through said secondzone and out of said column; and

(h) collecting said hydrocarbons at the upper part of said first zone ofwater, and drawing said hydrocarbons from said column.

3. A continuous method as set forth in claim 2, where in the first upperzone is maintained above 212 F. under pressure conditions.

4. The continuous method as set forth in claim 3 further comprising thesteps of dividing said first upper zone into an upper and lower area,both areas containing heated water with steam introduced thereinto, andcollecting said hydrocarbons in the upper part of said lower area.

5. A continuous method as set forth in claim 4, further comprisingmaintaining said second zone open to the atmosphere at the bottomthereof and flowing tailings and water through said bottom opening.

6. The method of claim 5, further comprising flooding the second zonewith water so as to eliminate the need for a variable orifice at thebottom opening by maintaining pressure levels above said orifice above apredeterminal level.

References Cited UNITED STATES PATENTS CURTIS R. DAVIS, Primary Examiner

